Which is Faster: ATA100 or SCSI UltraWide?

[Thelonious]

Greetings,

I currently have 2 Quantum Viking II's (9.1 and 4.5 gig), which I believe are Ultra2 (80MB/s) drives, but I only have a FirePort 40, so I'm limited. I recently broke down and bought an IBM 75gxp 30 gig cuz of a good deal.

Few questions:
- Is ATA100 faster than UltraWide(40MB/s) or Ultra2? If I just looked at pure numbers, ATA100 would be faster, but somehow I'm not sure if that's the case.

- Is CPU overhead of ATA100 high enough that even if it is faster, SCSI is a 'better' choice?

- Recommendations for a good and inexpensive Ultra2 SCSI card?


I'm upgrading my system next week, so I'll be reinstalling everything. One reason I ask, is the IBM drive is so much quieter and I would like to use it as a main drive...but I've gone for this long with the noise of the Quantums, speed rules all .

Thanks,
The|onious

 

[spellbound]

I'm no expert but I recently made the decision to add SCSI support to my system. For the most part speedwise ATA-100 and Ultra2 are probably about the same. Good SCSI drives usually have a faster seek time and more cache but the fast ATA-100 drives are pretty fast and have good throughput. CPU overhead is about the same as well. For me the advantage with SCSI is it's ability to multitask. IDE has to switch between devices on a channel and even if you set each drive or device up on a separate channel SCSI multitasks better.

For most average use it's probably not worth it to go SCSI and the IBM 75GXP drives (I have a 45GB version) are fast, quiet and inexpensive. For me I am adding a SCSI CD-RW and drive for my OS and apps and will use the GXP for data. For you, I don't think you'll notice much if any difference in speed as long as your GXP is using ATA-100 & UDMA.

If you do want a decent inexpensive Ultra2 controller, I purchased the Tekram 390U2W for $89 shipped at http://www.microstandardusa.com

 

[rootaxs]

SCSI would fare better because of two obvious reasons:

1) If you thrash your disk a lot (e.g. manipulating large files) the on-board cpu on a SCSI controller will help offload the load on your main cpu

2) SCSI's are rated to support the speed mentioned (and the disks *do* support the rated speed). For IDE disks, though ATA100 is already available, no harddisk to date supports this speed. Right now even ATA66 disks don't reach the theoretical maximum throughput the ATA66 interface has to offer.

 

[spellbound]

Perhaps I am wrong but if you are using DMA, CPU overhead on an IDE disk is quite low.
Sure you won't get 100MB throughput on an ATA-100 drive but the real world throughput
(maybe 40MB or so) is still pretty impressive for the price. You can buy 160MB SCSI
drives and controllers but you probably won't see that kind of bandwidth utilized unless
you have a RAID setup.

I still think that for most average users a good fast 7200rpm IDE drive like the GXP's
makes the best choice as it's quite cost effective. If you have a special application
where you can take advantage of the lower seek times, additional throughput and multitasking
ability that SCSI has to offer or if you have more money to spend and want the absolute
fastest then SCSI would be worth it.

I'm going to have my own chance to make a real world comparison soon as I'll be migrating
from an IBM GXP to an Ultra2 (80MB) controller and a U160 drive.

 

[monopoly]

SCSI for both I/O, multitasking capabilities and throughput.

Now some IDE ATA66 are pretty snappy but,

Adaptec U2W and good 80mb LVD capable drives are pretty speedy. Not to mention the fact that you can play music, Burn a CD, work in Word, surf the net and download at the same time without much burden on the CPU and without nary dropping a single bit. Come to think of it, you could probably even play a good Q3 session and not notice too much degredation of system resources outside of memory usage.

 

[Thelonious]

Thanks for the input.

The general consensus seems to be for SCSI and I do quite a bit of multitasking and disk intensive stuff (or at least I would like to think I do ), so I'll stick with SCSI as my 'main' or boot drives if you will.

I guess I could have tested ATA100 vs UltraWide myself when my new toys get here, but thought I'd ask people with experience to save some time .

I guess my next upgrade should be a new SCSI card to finally use my drives to their potential.

 

[RichieZ]

Used to have a 15GB 75GXP, then I moved to an 18GB 36LZX, BLOWS IT AWAY!

 

[compuwiz1]

RichieZZZZZ, I have 2 9.1gig 36LZX in my system and my 30Gb IBM 75GXP cannot hang with it at all.

I have the 30gb for MP3 archiving.

 

[Possum]

Thelonious' Quantum Viking II's won't match his IBM 75 GXP in performance though. Quantum Viking II was my first SCSI drive, then some IBM UW, and ultimately the Quantum Atlas IV. Now I'm using an IBM 75 GXP.

 

[mastertech01]

I used IBM U160 drives on a 29160...now Im using the GXP's in Raid.. In comparison benchmarks with EASY SCSI, SISOFT, and HD TACH the U160 were dogs in comparison to the raid setup. However I still maintain all cd drives, zip drive, scanner, etc in SCSI for the overall efficiency of SCSI. You will likely hear many opinions on this but these were my findings. I run on the HPT 370 Raid controller and it is awesome. SCSI 320 will come out soon and will likely give this a run for the money, but guess what a couple 61 GB U320 drives would cost in comparison to these GXPs as well as the fortune it will cost for the controller.. LOL 2nd mortgage time!

 

[Thelonious]

Well, I finally got a chance to compare performance after the arrival of my new parts. Unfortunately, I found out only my 4.5 gig Viking II is Ultra2 while the 9.1 gig is only UltraWide.

According to HDTach, Sandra, and some WinBench benchmarks, the IBM gxp pretty much cleans up the Viking II's. GXP averaged 29kbps in Sandra while Viking IIs only got 14kbps. GXP also had higher burst (around 78-79 mbps to 32-33 mbps of VII) and lower access time. In Sandra, interestingly it rates the Viking II's performance under that of ata66 .

Also, after getting a new SCSI controller (Tekram 390-U2W), ultra2 Viking scores remained the same. Anyone know what could be the problem? I'm not quite sure which cable is the designated "Ultra2" cable. I'm currently using one that has twisted pairs in it since that's the only thing I could find from research, but the cable is damn long.

For now, I'm going to go with the IBM gxp and use it more extensively. Heh, I don't think I've stuck to one OS or one drive since I built my system in late Dec.

 

[greg2]

Hello,

Speaking of that IBM drive, I was hoping I could get some advice.

I just built a new system and it works ok, but its not using the Promise ATA-100 Driver because Windows ME won't detect a "PCI Massive Storage Controller" like it says that it should in the manual. The MB is the new Gigabyte GA-7DXC (DDR compatible) with a 1.0 Ghz Athlon T-Bird chip, with an IBM 45GB ATA-100 HD.

I did try connecting the 40pin/80connector cable both ways from MB to HD, rebooted numerous times, tried to detect new hardware, tried adding hardware manually (added SCSI controller, with Promise ATA-100 driver, windows ME told me that it installed successfully but then device manager still shows no scsi controller). I did download the drivers on the web but they don't have any .exe files. (The manual did specify that to check a proper install of the driver to see if a "scsi controller" was in device manager, there is none despite my efforts).

I've tried my darndest on this, and would really appreciate any help anyone can give.

Thanks for reading this,

Greg

 

[kw3i]

scsi but you can find more on www.storagereview.com about this

 

[mastertech01]

Perhaps your controller isnt fully seated, or its not in a buss mastering slot or there is an IRQ conflict. Make sure it is on an independent buss mastered slot, assign an IRQ to the slot if necessary thru bios, and let the bios set your IRQs, not windows and give that a shot.

 

[kyoshozx]

Thelonious,

It looks like your scsi drives are a bit old. As you can see from your benchmarks that your ibm drive is faster. There isn't anything wrong with your setup it's just you can't expect old generation scsi's to outperform current generation ide's. Viking II is a pretty old drive should be at least a couple years old. The IBM is still a pretty new drive. I would recommend you using the IBM as your main drive.